The present invention relates to a system for judging a possibility of collision to an obstacle in front of its own vehicle, and warning the vehicle of the possible collision.
Conventionally, there have been filed many patent applications, for example, Japanese Patent Publications No. H05-181529 and No. H08-254577, for disclosing a collision avoiding system for avoiding a possible collision between vehicles, and disclosing a collision predictive system for alerting a vehicle driver of a possible collision. Most of these applications disclose systems for judging a possible collision to the obstacle in front of its own vehicle and alerting the vehicle driver to take an action for preventing the collision.
All of the systems automatically actuate engine brakes of its own vehicle and alert the driver of the subject or its own vehicle of an emergency. As it is alerted, the driver may turn a steering wheel and/or rapidly press a brake pedal for collision preventive action. Thereafter, the driver may turn on hazard warning lights to warn a driver of a following vehicle. Accordingly, there is a delay of time for the collision preventive action of the driver of the subject vehicle to the driver of the following vehicle to aware an emergency ahead, so that the driver of the following vehicle sometimes can not take a proper action for the emergency braking and/or the emergency steering. As mentioned, since the emergency warning to the following vehicle is delayed, even if the collision between the subject vehicle and a preceding vehicle, i.e. Obstacle, can be avoided, there is still a possibility of a collision between the subject vehicle and the following vehicle.
The present invention has been made to solve such a problem and an object of the present invention is to provide a vehicle collision warning system which estimates the possibility of vehicle collision and alerts a driver of a following vehicle to take an action for avoiding a collision when the possibility of vehicle collision is high.